AIM use & issues – owenduffy.net

AIM 916 produces internally inconsistent results

AIM915a was recently pulled from the distribution site and replaced by a new release, AIM916.

AIM916 chokes on some calibration files created with earlier versions, so again historical scan data is rendered worthless. Note the illogical diagnostic message… typical AIM quality.

I cannot recall ever finding a new release that did not have significant defects, commonly inconsistency between displayed values. In the common theme of one step forward, two steps backwards, this version has defects that were not present in AIM910B.

This problem existed in AIM915a, it persists in AIM916.

Let’s review the internal consistency of this part of the display screen.

Most of the values given above are calculated from a single measurement value, and should be internally consistent. That measurement value is translated to different quantities, many based on the stated Zref (50Ω in this case). Continue reading AIM 916 produces internally inconsistent results

Last update: 17th February, 2019, 12:49 AM

AIM 915a produces internally inconsistent results

AIM915 was recently pulled from the distribution site and replaced by a new release, AIM915a.

This problem existed in AIM915, it persists in AIM915a.

Let’s review the internal consistency of this part of the display screen.

Last update: 7th November, 2018, 8:57 AM

AIM 915 produces internally inconsistent results

AIM914 was recently pulled from the distribution site and replaced by a new release, AIM915.

Let’s review the internal consistency of this part of the display screen.

Last update: 10th October, 2018, 8:19 AM

AIM 914 produces internally inconsistent results

A new release, AIM914 appeared recently.

In the common theme of one step forward, two steps backwards, this version has defects that were not present in AIM910B.

Let’s review the internal consistency of this part of the display screen.

Most of the values given above are calculated from a single measurement value, and should be internally consistent. That measurement value is translated to different quantities, many based on the stated Zref (75Ω in this case). Continue reading AIM 914 produces internally inconsistent results

Last update: 9th October, 2018, 9:43 AM

AIM system – AIM912 initial checkout

Given that most versions of the AIM software that I have tried have had serious defects, I approach the latest release, AIM912, with caution.

An interesting opportunity presented when a correspondent sent me some .scn files captured from an AIM4170B using AIM912.

Above is the correspondents .scn file opened in AIM912. Continue reading AIM system – AIM912 initial checkout

Last update: 13th February, 2018, 9:03 AM

Accuracy of AIMuhf system – AIM910B vs several recent versions on a ferrite cored inductor

At Accuracy of AIMuhf system – AIM910A vs several recent versions on a ferrite cored inductor I reported significant problems reconciling several recent versions of AIM software measuring the same inductor. Continue reading Accuracy of AIMuhf system – AIM910B vs several recent versions on a ferrite cored inductor

Last update: 29th July, 2016, 5:01 PM

Characterising an unknown ferrite toroid

The ‘unknown’ toroid is wound with a single turn and measured with a VNA, an AIMuhf in this case.

Of interest in the first instance is the apparent inductance of the single turn winding at low frequencies where typically permeability µ is fairly constant and core loss is fairly low. Continue reading Characterising an unknown ferrite toroid

Last update: 26th December, 2015, 9:01 AM

Accuracy of AIMuhf system – AIM910A vs several recent versions on a ferrite cored inductor

Yet another release of AIM software is available, 910A at the time of writing. I have downloaded and tested 8 versions this year, most have been wanting. Again, there is very little detail on what has changed and likely impact on historical measurments.

A quick set of measurements was made on my test inductor pictured above. Continue reading Accuracy of AIMuhf system – AIM910A vs several recent versions on a ferrite cored inductor

Last update: 26th December, 2015, 9:01 AM

2.4:1 balun design failure

A lost soul searching for enlightenment on impedance transformation sought advice on a transformer at 2.4 : 1 BALUN.

Inevitably one of the forum experts counselled:

Assuming your quad is a single-band HF antenna, a conventional transformer using #2 powdered iron would be my choice for the balun function. The reactance of the secondary winding would need to be at least 600 ohms.

So, let’s put the forum expert’s advice to a practical test.

Fleshing out the proposed solution

I have at hand a T200-2 core, so lets calculate the secondary turns to satisfy the proposed solution.

Above is calculation from a popular online calculator. For 14MHz, the secondary should be at least 23.8t. We will use 24t. Continue reading 2.4:1 balun design failure

Last update: 26th December, 2015, 9:01 AM

A walk through of a practical application of AIMuhf/AIM900A #2

I mentioned at A walk through of a practical application of AIMuhf/AIM900 that I wasn’t all together happy with feed point R at resonance, at 40Ω it was perhaps a touch high for a 2m quarter wave ground plane on a largish vehicle roof.

Repeated measurement of the DC resistance from the coax plug sheild to car body yielded unstable resistance ranging from 1 to 10Ω. If stable low DC resistance is not achieved, this feed line won’t work properly for RF. Continue reading A walk through of a practical application of AIMuhf/AIM900A #2

Last update: 26th December, 2015, 9:01 AM